The long-term objective is to understand the overall control of gene expression in animal cells during cell growth, differentiation, and infection or transformation by tumor viruses. With an emphasis on specific genes whose activities are altered during these processes the immediate objectives are to elucidate the nature and mechanism of action of the factors which regulate transcription of a number of key genes during these processes, thus leading to an understanding of the intracellular signals and pathways important for control. The genes and regulatory mechanisms to be analyzed include: (1) tRNA and 5S RNA genes, stimulated during growth responses; (2) histone genes, activated during the S-phase of the cell cycle; (3) cellular proto-oncogenes (c-myc and c-fos), activated in response to growth stimuli; (4) "early" and "late" genes of DNA tumor viruses (adenovirus, herpesviruses), activated by viral immediate early (oncogene) products; (5) viral immediate early genes, activated in response to host factors; and (6) immunoglobulin genes, temporally regulated during B-cell differentiation. These genes will be studied in response to growth-promoting or differentiation-inducing factors and in various differentiated, transformed, or virus-infected cells. Guided by ongoing studies of the transcription and regulation of specific genes in cell free systems, including the structural and functional analyses of various transcription factors, our specific aims for the various genes are: (2) to identify and purify the basic factors necessary, in addition to corresponding RNA polymerases, for accurate transcription of purified DNA templates; (2) to identify and purify viral-coded or induced, tissue-specific, and cell-specific factors involved in regulation (using both DNA and chromatin templates, as well as direct DNA binding assays); (3) to analyse in detail the sites and mechanisms of action (site-specific DNA or factor interactions, alterations of kinetic parameters in transcription, etc.) of both basic and regulatory factors; (4) using functional and biochemical/immunological assays, to monitor alterations in the activities, structures, concentrations, or subcellular localizations of the factors during the aforementioned processes; and (5) to clone the genes for key factors to study their structure, regulation, and in vivo regulatory functions.